(CNN) -- Bahrain´s King Hamad bin Isa al-Khalifa has imposed a three-
month state of emergency in the island nation, effective Tuesday,
according to the state news agency.

The moves comes amid uncertainty in Bahrain, after foreign troops
arrived to help the government quell weeks-long protests in the
Persian Gulf kingdom.

Saudi Arabia and the United Arab Emirates sent troops Monday
to "protect the safety of citizens," the Bahraini government said.

But some in the capital city said Tuesday they did not need the added
protection.

"We don´t understand why these troops are coming in," said a 28-year-
old blogger in Manama. "We have an army and police. We do not need
troops from other places. Opposition leaders have called this an
invasion. An act of war."

Like others in this report, the blogger said he did not want to be
named because of fears of retribution.

Another man from the town of Hidd, who wanted to be identified only
by his first name, said he feared the troops would just inflame the
already tense standoff.

"I really hope things work, but I don´t think foreign troops will
solve anything," said Abdulrahim. "It will probably lead to more
violence."

But a 25-year-old banker from Manama said she welcomed the presence.

"It gives us peace," the woman said. "Maybe these protests will
finally end. These protesters say they are peaceful, but I have seen
them carrying sticks and knives. They are blocking the streets so we
cannot get to work. They are criminals and this has gone on for too
long."

The protests, which started on February 14, are part of a series of
demonstrations that have swept across the Arab world this year,
toppling the leaders of Tunisia and Egypt. But it was not clear
whether any other country had taken the step of calling in foreign
troops for help.

The movement of forces came on the same day that protesters seized
control of a key part of the capital city, Manama, a Human Rights
Watch official said.

Medical officials said at least 36 people were injured in clashes
Monday, many of them wounded by projectiles from pellet guns.

The Bahrain Financial Harbour was still shut down Tuesday morning,
said Faraz Sanei, a researcher with the group. But the extra troops
were not visible in the city.

"There are areas of the city that are being controlled by vigilante
groups armed with sticks and batons. The patrols seem to be
sectarian," he said.

"Any time civilians take up arms and take matters into their own
hands or threaten violence it is of great concern," regardless of
their political affiliation, Sanei said.

The nation´s Independent Bloc of lawmakers called on Bahrain security
forces to intervene to protect national security and stability, the
Bahrain News Agency reported Sunday. The bloc is composed of the 22
pro-government members of the lower house of the legislature.

"Extremist movements are resorting to escalation and sectarian
mobilization, which led to an unprecedented disruption of security
and hostile sectarian polarization at health and educational
institutions," the group said in a statement.

On Sunday, clashes between protesters and security forces resulted in
the hospitalization of more than 1,000 people, human rights activists
said.

The unrest prompted the U.S. State Department to warn Americans to
consider leaving the island nation. The United Kingdom, too, has
urged its residents not to travel there.

Last month, U.S. President Barack Obama welcomed plans by King Hamad
to make changes to his cabinet and proceed with reforms.

But a few days ago, U.S. Defense Secretary Robert Gates cautioned
that "baby steps" would not be sufficient to meet protesters´
demands.

Bahrain is the key banking and financial center in the Gulf. It also
plays a crucial role in U.S. defense interests in the region. The
U.S. Fifth Fleet is headquartered in Bahrain, and Bahrain is the only
Arab state to have led one of the coalition task forces that patrol
the Persian Gulf. U.S. military access to Bahrain also supports
operations in Iraq.

An underlying concern in this issue is that Iran, an overwhelmingly
Shiite state, could seize the opportunity to meddle in Bahrain´s
internal affairs. Bahrain has a Shiite Muslim majority population,
but its rulers are Sunni Muslims.

On Tuesday, an Iranian Foreign Ministry official criticized the
arrival of Saudi troops as an "invasion," Iran´s Press TV reported
Monday.

Saudi Arabia´s eastern province is home not only to many of the
country´s rich oil fields but to its largest concentration of
minority Shiites as well.

In recent weeks, Shiite demonstrators there have protested the Saudi
government, whose leaders are overwhelmingly Sunni.

The Saudi government would presumably be concerned that any uprising
by Shiite Muslims in Bahrain could inspire the Shiite population in
nearby Saudi Arabia to follow suit.

During protests in Bahrain, moderates have been demanding a
constitutional monarchy, and hardliners have called for the abolition
of the royal family altogether.

But pro-government members of parliament have asked King Hamad to
enforce a curfew and deploy security forces across the country,
saying the protesters´ motives are far more sinister.